Police have released CCTV images of two men they believe can help their investigation into the murder of a truck driver five months ago.

Keith Cini, 69, was bludgeoned to death by intruders in his home in Badgerys Creek, in Sydney's West in May. His wife Lucy was also beaten in the early morning home invasion and was found by police with head injuries and a broken wrist. Police believed at the time that the intruders had used clubs in the attack.

The new photos show one man in a baseball cap and blue, hooded jumper entering and leaving a service station in Narellan in Sydney's southwest. Police describe the man as of Caucasian appearance, aged in his 20s and of slim build, between 180cm and 190cm tall.

The other photos show another man, wearing a back-to-front baseball cap in a taxi heading towards Narellan. He is thought to be in his early or mid-20s, of thin build and with light brown or blond hair.

Police are keen to speak with two men seen at a service station in Narellan in Sydney's Southwest the night before the murder

Police are keen to speak to the two men and are appealing to the public to help in identifying them.

They believe the men left the petrol station in a light-coloured sedan heading towards the Badgerys Creek area in the early hours of Friday 30 May.

'This investigation is going very well and we're confident we are getting closer to finding the people responsible for Mr Cini's murder,' said Detective Superintendent Mick Willing on Friday.

'No doubt there are many people out there who will recognise these two men. If you do, please do the right thing and get in touch by contacting Crime Stoppers.'

Police are appealing to the public to help them identify the two men, one seen here in a baseball cap in a Sydney taxi

Police say this taxi with one person of interest in a baseball cap (right) was heading towards the Narellan petrol station in Sydney the night before the murder

This man entering the petrol station is described by police as caucasian in appearance and aged in his 20s

Mr Cini, operated Keith Cini Pty Ltd freight company and a piggery from his semi-rural property. On the night of his murder, the thieves broke into his home and demanded money from Mr Cini’s safe, where he reportedly kept takings from his pig farming business.

Family, friends and work colleagues were in shock over his violent bashing, describing Mr Cini as 'irreplaceable'.

'I couldn't talk of any better man,' said Mr Cini's best friend, Charlie Zahra, after his death.